Manchester United again struggled against a back five as their newly promoted hosts exploited a set-piece weakness Hull scored nine league goals from set plays last season, the joint-fewest in the Championship. Yet two in 21 minutes earned them a famous victory over Manchester United on Saturday. It was a disastrous start to the campaign for the visitors. While Michael Carrick said before the game it would not be easy , he would not have expected victory being so straightforward for Hull. It wa…